In the recording, which was made 15 minutes before the Washington Post reporter arrived at the embassy, the Saudi officials can be heard "[discussing] how to execute Khashoggi. They are reviewing their plan, which was previously prepared, and reminding themselves the duties of each member," according to columnist Selvi.

"There is also evidence from the period after the killing. Turkey has the international phone calls made by the 15-member Saudi hit squad," Selvi added.

On the first tape, also confirmed by Selvi, the sound of Khashoggi's "desperate attempts to survive" could be heard as he was strangled for seven to eight minutes, the reporter claimed.

Other factors that appear to discredit Saudi Arabia's claim the murder was premeditated include the presence in the room of a forensics official with experience in dismembering bodies, and a body double to fake Khashoggi's exit from the embassy.

It comes as dozens of people paid homage to Khashoggi in a symbolic funeral on Friday in Istanbul, where the 59-year-old was killed last month.

In the absence of a body, the crowd gathered in front of an empty place traditionally reserved for the coffin at Fatih mosque, AFP journalists reported.

Khashoggi, a critic of the Saudi leadership, was last seen entering the kingdom's Istanbul consulate on October 2.

Turkish officials say he was strangled and his body dismembered.

"We decided to hold the prayers as we are convinced that his body will never be found," Fatih Oke, executive director of the Turkish-Arab Media Association (TAM) of which Khashoggi was a member, told AFP.

Saudi prosecutors on Thursday announced indictments against 11 people and said a total of 21 individuals were in custody in connection with the killing.

But they exonerated the kingdom's powerful Crown Prince Mohammed bin Salman of involvement in the murder.